The present invention relates to improvements in fibrinolytic substances.
The coagulation of fibrinogen in blood results in fibrin clots, that is to say blood clots. Whilst the clotting of blood is necessary to stop the bleeding of wounds, it gives rise to thrombosis if blood clots are formed inside the circulatory system. Substances are known, some of which can be administered therapeutically which inhibit the formation of fibrin clots, e.g. heparin or the active principle of the venom of the Malayan pit viper. Most of these substances are either ineffective or at best weakly effective in dissolving fibrin clots once they have formed, and they can give rise to dangerous side effects. An enzyme, plasmin, will dissolve clots, but the normal plasmin concentration in human blood is too low to be effective in the short term. Plasmin formation can be stimulated by the administration of a protein substance, streptokinase, but this product is very expensive and not without side effects. Other substances are so exorbitantly expensive as to be of purely academic interest. Accordingly three exists a clear need for new substances having fibrinolytic activity, i.e., the property of dissolving blood clots, even if they are advantageous by comparison with the prior art in even one of the aforesaid respects. Such substances, would also be of value for laboratory purposes.
For many purposes such substances would be even more useful if in addition they had the property of inhibiting clot formation.
The present invention is based on the discovery of a new fibrinolytic substance or group of substances in bile.